Acquiring Volage, current and resistance with PC

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Vincenzo

Acquiring Volage, current and resistance with PC

Post by Vincenzo »

Dear all,
I need to use a PC data logger to measure everything, that usually is measured by using a compact multi meter, as DM9B Digital Multi-Tester produced by Meterman, voltage, current...
I need usually to measure signals coming from electronic devices, as analogical to digital convertes, 0-2.5V, 0.5-4.5V, 0-10V, 0-0.1V, 0-5V, 4-20mA, 0-20mA and so on, with great accuracy to test the converters and to calibrate the sensors and sometimes to measure AC current or higher voltages, 100V or 250V.
I prefer the PC based solution because cheaper. So I need a cheap solution for my needs.
I use pico TC08, I know it can measure 0-5V and 4-20mA, but not 0-10V.
I look forward pico answer.
Regards.

gruntman
Advanced User
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Joined: Thu Sep 28, 2006 3:50 pm

Re: Acquiring Volage, current and resistance with PC

Post by gruntman »

Vincenzo,

As you stated, you know that the USB TC-08, even though only has a input range of 70mV, can measure 0-5V and 4-20mA. This is possible by using resistors and current shunts. With resistors and current shunts, a single voltage data logger can be used to measure a wide range of voltages. If you need to measure 0-10V you simply use different resistors, same with different current. I recommend that you look over the PL1000 series terminal board manual (http://www.picotech.com/document/pdf/Sm ... sGuide.pdf) to see the formulas that you will need to use to convert the different types of measurement you want to log.

One thing does stand out however and needs to be addressed, you mentioned that you want to measure higher voltage and the current on those lines. With these applications you need to connect differently. Do NOT connect the logger directly to mains lines etc. For higher current I would recommend using a clamp on current clamp to get the current on these lines. Then simply connect the clamp output to your logger (voltage output varies based on model of clamp so keep this in mind). For the high voltages look into purchasing a differential probe and connect it to the logger. While these two items will raise the purchasing price, safety is the number one concern with high voltages.

Regards,

Richard Boyd
Crag Technologies, Inc
http://www.pc-oscilloscopes.com

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